1. Field of the Invention
The present invention relates generally to methods and apparatus for securing tarps and more particularly to such methods and apparatus in which a cord or line is connected to a tarp at a selected location on the surface of the tarp.
2. Description of the Related Art
Fasteners for web-like articles, such as tarps, are known in the art. Fasteners such as those disclosed in U.S. Pat. No. 4,688,304 to Marcott; U.S. Pat. No. 2,939,195 to Carlson; and U.S. Pat. No. 3,913,186 to Ray et al. each incorporate a pair of interconnecting bodies which are disposed on opposite sides of a tarp or the like. The bodies are then connected to wedge the tarp therebetween and a line is attached to one of the bodies to secure the tarp. U.S. Pat. No. 4,393,558 to Herwegh et al. discloses a similar fastener for sheet material in which one of the bodies includes a spike which pierces the material. U.S. Pat. No. 5,033,170 to Ewert discloses a snap-on fastener for web-like articles in which one of the bodies comprises a circular button which snaps into a locking position in a corresponding circular hole in a frame. When the button and frame are placed on opposite sides of a tarp and the button is locked in the frame, a line is connected to the frame to secure the tarp.
Several patents to Hutton et al. disclose a plate which interconnects with a stud on opposite sides of a sheet to secure the same to a mattress. For example, U.S. Pat. No. 4,782,543 to Hutton et al. discloses attachment of flat sheets to water beds in which the plate is connectable to the ends of a pair of elastic cords.
Prior art devices for securing web-like articles such as sheets or tarps suffer from several disadvantages. First, few of the prior art devices utilize an elastic cord. When a pair of bodies are positioned on opposite sides of a tarp and secured thereto as described above, connecting one of the bodies to an elastic cord for securing the tarp would desirable. As noted above, one of the Hutton et al. patents utilizes an elastic cord. It, however, can only be connected to the fastener device at the end of the cord. It would be advantageous to be able to anchor one end of an elastic cord, stretch the other end until a predetermined level of tension is in the cord and then connect the cord to the fastener device at a location along the cord which maintains the tension level.
With respect to the fastener devices utilized in the prior art, the Marcott, Carlson and Ray et al. devices noted above each incorporate a button or stud which is placed on one side of a tarp opposite a frame having an opening therein. The tarp is secured by pushing a button through a large portion in the opening and thereafter sliding the button, and the tarp surrounding the button, to a smaller portion of the opening. Because the button does not positively lock with the frame, a secure connection to the tarp is not made.
Those devices which provide positive connection of the button to the frame, with the tarp therebetween, are difficult to use with thick tarps. While most are usable with relatively thin tarps, the openings in the frame in which the button is received may not be sized appropriately for a relatively thick tarp. It would be desirable to provide a tarp fastener having a clip or frame which positively connects to the tarp for a broad range of tarp thicknesses.